9. f2f3  9... g4h5  10. e1h4 This is one of the points of White's play, although it's less dangerous than it seems at first sight. 10... h8g8 [%c_effect g8;square;g8;type;Interesting;persistent;true] A fantastic idea, and not new to this game. Black loses the right to castle, but prepares Bg6 to take with the h-pawn. 11. c1f4 